Embodiments of the inventive concept relate generally to semiconductor memory devices. More particularly, embodiments of the inventive concept relate to nonvolatile semiconductor memory devices and related methods of operation.
Semiconductor memory devices can be roughly divided into two categories including volatile memory devices and nonvolatile memory devices. Volatile memory devices lose stored data when disconnected from power, and nonvolatile memory devices maintain stored data even when disconnected from power. Examples of volatile memory devices include dynamic random access memory (DRAM) and static random access memory (SRAM), and examples of nonvolatile memory devices include electrically erasable programmable read only memory (EEPROM), ferroelectric random access memory (FRAM), phase change random access memory (PRAM), magnetoresistive random access memory (MRAM), and flash memory.
Because nonvolatile memory devices retain stored data when disconnected from power, they are commonly used to provide long term data storage for electronic devices. For instance, flash memory is commonly used for long term data storage in devices such as solid state drives, cell phones, digital cameras, and personal digital assistants, to name but a few.
A flash memory typically comprises a memory cell array for storing data. The memory cell array typically comprises a plurality of memory blocks each comprising a plurality of pages, and each page comprises a plurality of memory cells sharing a common wordline. A flash memory typically performs erase operations on an entire block unit and performs read and program operations on a page unit. During a read operation, a flash memory temporarily stores a page of data from the memory cell array in a page buffer and then outputs the data from the page buffer. During a program operation, the flash memory receives a page of data, stores the received data in a page buffer, and then programs the stored data in the memory cell array.